Ag-Zn粉末的机械合金化和随后的热处理

摘要

Microstructural evolution during mechanical alloying of Ag and Zn, and subsequent heat treatments were investigated. The mechanical alloying was carried out in a SPEX 8000D miller. The microstructural characterization was obtained by X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The thermal behavior was studied using differential scanning calorimetry (DSC). Based on the results obtained, it can be concluded that at the early stages of milling was possible to detect theε,β,β′,αsolid solutions and remaining Zn. Later, theε,β,β′and Zn phases disappeared while the Zn concentration of theαsolid solution was strongly increased. After 7.2 ks of milling, the mechanical alloying process reached a steady state. During this period, both the composition and crystallite size of theαsolid solution remained practically unchanged. On the other hand, subsequent heat treatments of milled powders showed that the α solid solution could also be obtained by the combination of mechanical alloying and heat treatment. Finally, the evolution of the microstructure during milling and annealing was combined to propose an optimal processing route in order to obtain aαsolid solution.%　　研究了在机械合金化过程中Ag 和 Zn以及随后的热处理中的显微组织演变。机械合金化在SPEX 8000D铣床中进行。采用X射线衍射(XRD)﹑透射电子显微镜(TEM)和扫描电子显微镜(SEM)观察样品的显微组织。使用差示扫描量热计(DSC)研究样品的热性能。结果表明，在合金化初期的碾磨过程中能观察到ε，β，β′，α固溶体和剩余的Zn。随后，ε，β，β′和 Zn相消失，α固溶体中的Zn浓度剧烈升高。在碾磨7.2 ks后，机械合金化过程达到稳定状态。在此期间，α固溶体的组分和晶粒尺寸保持不变。后续热处理表明α固溶体也能够通过机械合金化结合热处理得到。最后，为了得到α固溶体，根据碾磨和热处理过程中样品的微观组织演变，提出一个最佳的工艺路线。